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Message-Id: <1468515848-34152-1-git-send-email-glider@google.com>
Date: Thu, 14 Jul 2016 19:04:08 +0200
From: Alexander Potapenko <glider@...gle.com>
To: dvyukov@...gle.com, kcc@...gle.com, aryabinin@...tuozzo.com,
x86@...nel.org, rostedt@...dmis.org, mingo@...hat.com
Cc: kasan-dev@...glegroups.com, linux-kernel@...r.kernel.org
Subject: [PATCH v1] x86, kasan, ftrace: Put APIC interrupt handlers into .irqentry.text
When building with CONFIG_FUNCTION_GRAPH_TRACER or CONFIG_KASAN, put the
APIC interrupt handlers into the .irqentry.text section. This is needed
because both KASAN and function graph tracer use __irqentry_text_start and
__irqentry_text_end to determine whether a function is an IRQ entry point.
Dmitry Vyukov has reported unexpected KASAN stackdepot growth
(https://github.com/google/kasan/issues/36), which had been caused by
the APIC handlers not being present in .irqentry.text.
Signed-off-by: Alexander Potapenko <glider@...gle.com>
Reported-by: Dmitry Vyukov <dvyukov@...gle.com>
---
arch/x86/entry/entry_64.S | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 9ee0da1..966b1a8 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -601,9 +601,20 @@ apicinterrupt3 \num trace(\sym) smp_trace(\sym)
.endm
#endif
+/* Make sure APIC interrupt handlers end up in the irqentry section. */
+#ifdef defined(CONFIG_FUNCTION_GRAPH_TRACER) || defined(CONFIG_KASAN)
+#define PUSH_SECTION_IRQENTRY .pushsection .irqentry.text, "ax"
+#define POP_SECTION_IRQENTRY .popsection
+#else
+#define PUSH_SECTION_IRQENTRY
+#define POP_SECTION_IRQENTRY
+#endif
+
.macro apicinterrupt num sym do_sym
+PUSH_SECTION_IRQENTRY
apicinterrupt3 \num \sym \do_sym
trace_apicinterrupt \num \sym
+POP_SECTION_IRQENTRY
.endm
#ifdef CONFIG_SMP
--
2.8.0.rc3.226.g39d4020
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